PB666

Quantum gravity.

Im still seeing space craft dodging and darting around asteroids that are way to close in space. Its millenium falcon stuff, Star Wars kiddie fodder. In terms of the physics, I see mother ships that have to have been assembled in orbit, I have a space factory, do they? lol. Any game that sees frequent and large-scale destruction of space property is unrealistic, IMHO, space property is hard to regenerate. Any war of destruction, the race that salvages wins. These guys start fighting, I just pull out a well defended ION drive system and start picking up all the pieces and shove them in a basket of chain-link. After it is all over I declare victory. There is one critique below that is relevant. To travel around space with excessive freedom according to physics you need to have infinite power (like a fusion reactor or a pulse fusion rocket), and the ability to accelerate that to high ISP. The problem is that there is no power system that humans have created that does not waste heat, thus the more power you transform the more heat you have to radiate. There is no known way, yet, to get around the physics. If your spacecraft is of the Orion type, then it ability to manuever is limited. If it is of the starfighter the your ability to deal with waste heat is limited. BTW if you are an Orion type ships you would not be in a group of ships, your thruster will kill your companions. I wish I am wrong, I have my own fusion based designs, but the problem is that someone needs to come up with a technology that proves the observation wrong. Until that technology appear, consider it impossible.

They don't call them delays, thats too offensive, they call them slips and slides and other cryptic terms.

Remedy domesticated felines, the real cause of the population dropping phenomena was two fold. The onset of the mini-ice age (people brought their farm animals indoors), a corrupt church. Aside from that the human kind has survived such disasters several time along its history. The spansih flu outbreak of 1916-1920 killed more people and was less predictable. I would replace b) with Cell phones, twitter and face-book accounts (unrestricted access to media) as the likely reason.

I didn't say it was probable, it one the extreme edge of possibility, as per what Diche was saying.

I don't believe in neobiogenesis, per say, but in terms of evolution, particularly molecular evolution, there is no doubt that evolution is occurring (look at STRs between fathers and sons in humans), that evolution has been occurring (just look at the recombination of HLA types as humans have spread around the world), and that it has been occurring for a long period of time (look at the mitochondrial tree, which a 5th grader could create a phylogenetic tree going back at least 200 million years). WHen I say I don't believe in neobiogenesis that is to say I don't know if it occurred here on earth to create current diversity, whether life was drop here, reached here. But I do believe that neobiogenesis occurred at least once in our galaxy and probably at least once in our solar system and likely several times on Earth, which is to say I don't know whether current life on Earth descended from an event or from a trans-planetary event. From that perspective you are correct, but saying that evolution does not exist, that is pretty far out on a limb.

The same, but I needed to point out to everyonee WHAT we are looking for when we look for _X_, we are not looking for octopi in some deep vent or a cute little xenopuppy. Whole the reasons of what humans are in terms of the ulitimate exploitative generalist are the same reasons there is the idea of a prime directive. If they are capable of understanding what you are . . .and they are not at the tech level of what you are . . .but might be capable . . . .then you have probably made a mistake that you will regret by contacting them. From a scientific point of view it does not matter the level of intelligence, life is a study of the variation not the 'what is it'. From a social-political point of view it makes a big difference. Thus you only need to know enough about intelligent life to give yourself a wide lee-way when interacting with new worlds.

You mean like the whale intelligence in Star Trek series. You have the metric wrong. To be intelligent of a level meaningful in a xenobiotic context you left out one very important point that most of these other examples lack in magnitudes. Humans are one of the most manipulative, environmentally exploitative, resource-heavy dependencies of any species that has ever lived on the planet. We leverage our intelligence with machines, beasts of burden, irrigation systems, roads, shipping. The most social ant in the world cannot skype another ant on the otherside of the world asking for advice on how to deal with anteaters. Other animals manage to leverage their cognitive facilities in a few directions. Crows are of advanced EQ and they can take clams and bust them on rocks, find clever ways out of cages, octopus are great at getting into things and escape and mimicry artist. Dolphins are able to sense prey blind and feed as if they had x-ray vision. Wolves work together in packs to take down prey several time their composite size. All these measures of skill and learning are not to be discounted. But the day the first human sat down and crafted an adze, hollowed out a canoe and went beyond the line of site to a new land, where he and his mate(s) learned to exploit new resources human-kind would see the power of serial problem solving that is magnitudes above the manipulative ability, at its peak in societies, compared to other animals. This is why we are here talking about these things and crows are not. There have been many crow level species since the dawn of the Earth, there has only been one space-race.

They can use whatever they want, I won't use an RL10-b2 to lift 28t to orbit , its simply a waste.

The reason is quite simple. The difference between the two engines is too great, the RS68A is a very very powerful engine, its great, fantastic, with two booster really great .. . . Its practically the only engine I use now. . . . . but the RL10b-2 is also a really great space engine meaning 95% Vorb to hyperbolic , but you need something in between to burn efficiently to orbit. This is why I brought up the discussion earlier about the RD150. If the D4H had a intermediate stage consisting of RD150 engines it would be the rocket to beat, PL to orbit would almost double. The three stages of ULA combined at launch produce 100x the thrust of the RL10b-2 where as the upper stage is 1/5th the total weight. a differential ratio of 1:20. The falcon 9 produces 10 times the thrust in the first than the second and the but the first stage is 549 whereas the second stage is 111, a differential ratio of 1:2. Thats a pretty big difference. A wide difference like that puts more work on the core. Note that the Falcon9 (expendible) gets 22t into orbit versus DH4 gets 28 t Unless ULA changes there configuration SpaceX is going to beat ULA, for the same sized or smaller rocket eventually they will get a higher payload into orbit.

Not an expert on these things, but 24 hours before launch isnt that big white part suppossed to be sticking strait up in the air?

Whoopsie. Algorhythms are like fine wine, you never truly know how well (or badly) it has aged until you finished the bottle. Inverted accelerometer seems like a bad thing, no .. . . is that just a cya excuse the fact that no-one wanted to put up rubels for another programmer on staff? i.e. you will know the next day.

13 is only unlucky if you use imperial units of measurement.

OK, . . . . A lighter launch rocket, 3-RL10b-2 on the back 40 tons into orbit (The addition of 12 tons of payload for the cost of 2 RL10b-2) it can easily be justified by a lower weight in the launch rocket (plus 800 dV of cryo left). RL10s are not like SSME, they are a pretty simple engine.

There are questions whether polywell is theoretically possible to stabilize, at least no-one seems to know how badly electrons which are supposed to maintain highest density at the center and the wells, are actually thermalized and wasting all the power generated in undesired hv.

yep.

YOu have to download the image to Imgur and then cut and paste the png file link.

Nice jibberish>

Hah, as for highlights, it will have street cred when its been tagged by at least 2 rival gangs.

I can come up with a design easily that does not need and RL10-b2 and a cheaper on that uses Kerosene and Oxygen. RL10-b2 is a space engine, it really not a go to orbit engine unless your payload in small. In fact why it took me so long to test the configurations was that all my rockets overshot the target velocity, I had to take the first stage apart and reduce the engines in them. lol.

Delta III second stage works fine, Delta IV second stage might work fine for a MEO orbit its a waste for LEO. [corrected] The RL10b-2 is a known thing, its only 277 kg, adding a second engine like the Russians do in similar circumstances is tried and true practice.

Anything can be a final burn to orbit, including an ION drive, however it silly to devote a whole stage to 1k m/s of dV (out of a total of 9500) just because its the most efficient engine you have, particularly when its burning 35' to prograde most of the time. Im am testing their model right now, shot up to 250 km and now correcting with an off angle RL10b-2 thats overloaded back to 200 because of the radial velocity. If you want to argue thats good, go ahead, I design rockets to get Kt in orbit, not 28k limping to orbit on its last stage to orbit. Let me clarify this so I don't get a pedantic response. In an orbit where the target orbital velocity is 7788 m/s an final stage to orbit can be any size, including 1 m/s dV if the previous stage leaves you at 7787 m/s and all you need it one. In terms of limit, it is literally the limit as thrust decreases the previous stage velocity at a given that an engine can place a payload in orbit. This is why we talk about burning vertically, you can burn your rocket vertically to keep up long enough to lose some fuel and gain a fraction of that thrust in horizontal dV, but that is unwise, the engine should be more powerful or the fuel should be smaller, if the fuel is to small to complete the task then the problem really is the engine. An ION drive in a 200 x 140 orbit can, if more powerful that the force of drag push a payload to orbit, but that is not a wise use of an ION drive since the time it takes to get the craft out of the muck it probably could push the payload out to Mars. Once the engine falls below the ability to push the craft to a viable periapsis and increase that periapsis it has reached its limit. Maybe ULA doesn't want to redesign a stage and things its just cheaper to Jimmy it into orbit with non-optimal equipment.

There are two other smaller options, you can use half the fuel but you would not reach orbit or the circularization burn starts at a higher velocity, you could use 70% of the fuel but your rocket would still be sitting pretty vertical for a long period of time. You could burn to a higher apogee and then allow the pitched burn to bring the orbit back to 200. As a circularization engine 28t payload to LEO200k is about the limit of RL10b-2s performance.

True, fission generates alot of deuterated water. What better to do with the water than make small H-bombs. But yeah if you watch IA you would have a tendency to believe that scale of fusion would be easy, of course when you don't currently have 100t to LEO system that works. . .its impossible. The argument this morning about RL10b-2 being used as a cricularization engine, yeah sure if you are dealing with a 15t payload, but to do any of the things we are talking about in this forum (lets say 80%) that payload is hideously small. I consider the threshold for colonizing space is the ability to put a 1 kt payload into space. I would say assembling a fusion reactor in space as within the next 100 years, impossible.

Have you looked at how our government is run lately?